1. Field of the Invention
The present invention relates to a variable valve system. More particularly, the present invention relates to a variable valve system having a device that can supply high pressure oil.
2. Description of Related Art
Generally, an automotive engine includes a combustion chamber in which fuel burns to generate power. The combustion chamber is provided with an intake valve for supplying a gas mixture containing the fuel and an exhaust valve for expelling burned gas. The intake and exhaust valves open and close the combustion chamber by a valve lift apparatus connected to a crankshaft. Also, in opening/closing the combustion chamber, a variable valve system is used to effectively control opening/closing timing of the valve. That is, the variable valve system varies valve opening/closing timing depending on the operation conditions of an engine to output appropriate power, to improve intake and exhaust efficiency, and to improve fuel consumption efficiency.
When the movement of the valve is controlled by hydraulic pressure in the variable valve system, if high pressure oil is not stably supplied at the right time, a movement difference of the valves between cylinders can occur. Also, if the pressure of the oil is not maintained at a predetermined level, the valve movement is not accurately controlled. Further, when oil leaks, a temporary operation failure of the variable valve system can be generated.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.